In the midst of an anesthetic shortage that has already forced postponement of lethal injection executions across the United States, Arizona says it has the drug in hand but is refusing to disclose where it was manufactured.

Federal judge Roslyn Silver ordered Arizona on Saturday to give the name of the drug manufacturer to Landrigan’s lawyers, but the state prosecutors refused, citing confidentiality laws for executions. Silver blocked the execution on Monday, saying more time is needed to consider the case, as the unidentified origins of the drug meant it could have been contaminated.

Only one pharmaceutical company in the United States, Hospira, currently manufactures sodium thiopental, but it is out of stock and will not be able to resume production until the first quarter of 2011.

Federal Justice Roslyn Silver was appointed to the bench by President William Jefferson Clinton and confirmed by The Senate in 1994.

Hospira Corp. produces all three of the pharmaceuticals used for lethal injections in The United States.